The invention relates to an apparatus for producing a corrugated pasteboard having a cover coating on at least one side, comprising a toothed corrugating element and a toothed corrugating counter-element co-operating therewith, a glue applicator and a drying apparatus.
In such an apparatus, which is known for example from German Patent Specification No. 26 11 325, the corrugation of the paper web is effected by two heatable corrugating cylinders meshing with one another which are pressed under high pressure against one another. A glue applicator roll transfers glue to the corrugation crests of the corrugated paper web looping around the lower corrugating cylinder. An arriving cover coating web is pressed against the glued corrugation crests by the heatable presser cylinder. A holding device acting in the region of the lower corrugating cylinder ensures that the corrugated web is held on the cylinder surface of the lower corrugating cylinder. In this known apparatus it is disadvantageous that the deformation of the paper web by the two co-operating corrugating cylinders takes place over a very small zone of engagement, so that the embossing time of the paper is very short and a high application pressure is necessary. The consequences are heavy wear of the corrugating cylinders and also of the presser cylinder which passes the cover coating web, high generation of noise and a susceptibility of the entire roll system to vibration, whereby the quality of the corrugated pasteboard is disadvantageously influenced. Moreover mechanical guide devices are susceptible to wear and require frequent readjustment.
the invention is based upon the problem of improving the known apparatus to the effect that noise generation and roll wear are reduced, the quality of the corrugated cardboard is improved, and paper consumption and difficulties of adjustment of parts of the apparatus are reduced and the feed and introduction of the paper web are facilitated.